Have you tried any vacuum advance? Looks like it is disconnected in your pic. In my experience, vacuum advance will let an engine idle cooler, and not ping under load since it goes away then. Retarded timing builds heat. Although vacuum advance may bring back the idle surging - easy enough to try anyway, if you haven't already...

I would agree, the distributor or vacuum advance is likely your problem, and the more aggresive cam may be part of the problem as well.

I ran the following HYD Roller cam in my Long Ram engine with excellent results, it's a low maintainance mild street build, bascally stock with better more modern componants, the engine is a 413 bored to 426 cubes, stock stroke, stone stock 2903 factory carbs with factory jetting:


Comp Cams XFI series with TK series lobes that are solid lifter design lobes that they use with hydraulic roller lifters very successfully on the street with these B/RB motors. These lobes are a little bigger and a little more aggressive that will make more power and torque at a lower RPM but still rev up to and above 6000 RPMs. These lobes have between 236 duration @.050 up to 242 @ .050 with .630 lift at the retainers with 1.5 ratio rockers or .672 with 1.6 rockers running 111 Lobe Centers.

I'm sure you know to make sure that the heads are set up for cams with this type of lift and to use a valve spring with pressure that will have around 140 to 175 lbs. on the seat and between 325 to 400 lbs opened and at least .060 and not more than .100 to coil bind.

I dynod it with Short Rams and Long Rams, here's one of the Long Ram runs. You could change the HP vs TQ figures up or down 5-10 with timing changes.

I have had the vacuum advance connected a couple of times, but decided to leave it off until the ignition had a good baseline setting and the surging was taken care off.
There is still some surging present but nothing serious. With the stock convertor the first second is sometimes a bit tricky, keeping the engine idling when putting the tranny in gear, from the driveline 'grab', but after that the engine idles good with a nice lope in Drive.

I will play with the vacuum advance now that I've found a setting that the motor doesn't ping with anymore.
Hopefully I can cool it down a bit more but I doubth that does much for the underhood temps.

I've been waiting for our long ram guru to jump in. What thoughts have had about about playing with cam timing, seems like a long ram motor is a perfect candidate for this type of tuning.